1. Field of the Invention
The present invention relates to headlight assemblies in general, and more particularly to headlight assemblies the light beams of which can be adjusted or switched at least between their high-beam and low-beam positions.
2. Description of the Related Art
There are already known various constructions of motor vehicle headlight assemblies switchable between their low-beam and high-beam operating modes. A typical assembly of this kind includes a housing, in the interior of which there are arranged a reflector component and a light source component. In many motor vehicles, especially recently built ones, the light source component is movable relative to the reflector between its position for the low-beam, and that for the high-beam, mode of operation of the headlight assembly.
An example of a headlight assembly of this kind is disclosed, for instance, in the German patent application. DE 44 35 507 A1. In the headlight assembly revealed there, the light source component is moved, for the purpose of switching between its position corresponding to the low-beam operating mode, and that assumed in the high-beam operating mode of the headlight assembly, both in the direction of the optical axis of the reflector component and transversely to that optical axis. In order to accomplish this movement, there is provided an adjusting member that causes the light source component to pivot relative to the reflector component about a light source pivoting axis. This light source pivoting axis extends substantially perpendicularly to the optical axis of the reflector component and horizontally as considered in the orientation of the headlight assembly when in normal use, at an offset from the optical axis. It is also disclosed there that the adjusting member can be constructed an electric motor, a hydraulic or pneumatic driving unit, or even as an electromagnet.
In the last instance, the electromagnet or solenoid constituting the adjusting member must be relatively large and be dimensioned so as to exhibit a high degree of sturdiness. The effective displacement of the movable part of the electromagnet must be sufficiently large to cover the distance required for moving the light source component between its position for the low beam and that for the high beam. While it would be possible to shorten this required distance by the use of a suitable transmission, this approach would have a negative side effect of requiring the electromagnet to overcome a considerably greater force than in the absence of such a transmission and, consequently, to be built even stronger than before. It will be appreciated, though, that the larger and stronger the electromagnet is, the heavier it is and the greater amount of space must be available for it to occupy. Yet, in this construction a smaller and lighter electromagnet would not be able to reliably perform the function that is expected from it, that is that of the aforementioned adjusting member that switches or moves the light source component between its low-beam and its high-beam position relative to the reflector component.
Moreover, the German patent application No. 44 35 507 A1 mentioned before does not include any indication whatsoever that the adjusting member should or even could be used in the context of the headlight assembly revealed there for any other purpose but for that stated, that is that of moving the light source component relative to the reflector component. As a matter of fact, the disclosure of this application is such as to dissuade a person familiar with its contents from even contemplating any such other use.